This invention relates to apparatuses and processes for improving the microstructure of electrically conducting materials. More specifically, the present invention relates to an apparatus and process for substantially improving the grain size of electrically conducting materials such as metals and alloys and for forming grain boundaries in a directional or nondirectional manner, whichever is desired.
Electrically conducting materials such as elemental metals, metallic alloys, and some ceramics, can be characterized by their microstructure, which includes phase morphologies. The particular microstructure of a specific sample of material depends on many variables, one of which is how it was processed. For example, MAR-M246(HF) (a nickel-based superalloy) was melted and solidified with the process described in this patent. The microstructure was enhanced by various changes in phase morphology. These included eliminating gamma-gamma prime eutectic phase islands from the section of rod which was melted and solidified with this process. Also carbide morphology was changed from large script-types to extremely small, fine, extremely well dispersed carbides. Other rods of MAR-M246(HF) with an original small, fine block carbide morphology were processed in this same manner. The resulting carbide morphology change after melting and solidification was the same; extremely small, fine, and extremely well dispersed carbides.
The microstructure of these materials, and/or relative orientation of the boundaries of the grains of these materials, gives them different mechanical properties. In some applications nondirectional or equiaxed microstructure is preferable to more high directional structure. In other applications, the reverse is true, such as when the material may see greater stresses and be subjected to greater fatigue in one direction than in another.
The present invention is an apparatus and a process for significantly improving the microstructure of electrically conducting materials by reducing the size of the material's grains and for determining the microstructure of the material which includes establishing the desired relative directionality of the grain boundaries.
It is an object of the present invention to improve the microstructure of electrically conducting material. It is another object of the present invention to rapidly melt and quickly cool electrically conducting materials. It is still further an object of the present invention to evenly melt and unevenly cool electrically conducting materials when a higher degree of directional grain growth is desired.
It is yet a further object of the invention to establish very fine carbide morphology and the desired microstructure of a particular sample of electrically conducting material.
These and other objects of the invention will become apparent to someone skilled in the art of apparatuses and processes for improving the microstructure of electrically conducting material upon reviewing the following description of the invention.